Phonograph turntable drive



Feb. 7, 1939. ERwO QD 2,146,253

PHONOGRAPH TURNTABLE DR I VE Filed June 30, 1938 mam aim rinned Feb. 7, 1939 Joseph} Chicago, 111., name to, The Webster Company, Chicago, 111., a corporation oflliinois Application June so, 1938; semi N... 210.741 a 4 Claims. I (cask-so) The principal object of this invention is to provide" an improved releasable driving connec tion between a spindleand phonographqturnp, table. An outstanding feature of this inven- 5 tionis the ease and simplicity of producing and a l y assembling the necessary parts as will appear by reference to the accompanying drawing, where- Figure l is a view in vertical section through a turntable in operative relation to its driving spindle, the latter being shown in elevation;

Fig.2 is an enlarged horizontal section taken on line 2--2 of Fig. 1; a

Fig. 3 is a detail in perspective of the transmission unit;

Fig. 4, which is a view similar to Fig. 2, shows a transmission unit of modified construction; and

Fig. 5 is a detail in perspective of the transjf mission unit shownin Fig. 4.

tion here illustrated, a spindle S, rotated through a geared wheel I which is turned by a worm shaft 8, is mounted upon a thrust bearing 1, and extends up through a second bearing 8 which may be afllxed to a platform P. Fitted upon the upper end of the spindle is a turntable T equipped with a hole It capable of receivng the tip I! of the spindle which is of reduced diameter above s a shoulder. 18 which is beveled for reasons which will presently appear. The turntable is adapted to rest uponthe shoulder when mounted in operative position. a l

"In connection with the turntable is a circular wall 20 which may constitute a hub therefor,

such a wall enclosing a transmission unit" which maycomprise a plurality of elements E extending between the spindle and turntable wall. As

shownin Figs. 2 and 3, each element may be in the form of a leaf spring having end wings 2| and a central bowed portion 22, the two elements, in the absence of the spindle, exerting little or no pressure against eachother or the hub. when positioned within the circularenclosing wall, theymay remain somewhat loose with their bowed portions touching at the corl ners 23 (Fig. 3). When the spindle isinserted through the turntable, the tip proceedsfirst between the central portionsof the transmission elements, then the beveled shoulder, and-finally the spindle body itself which thrusts the bowed 1 portions of the springs apart. In so doing a radialforce is exerted which is resolved into component forces along the wings with a resulting frictional engagement between the wing ends In the particular embodiment .of my invenand the circular wall. Under conditions the transmission elements [are tensi0ned 'sutficiently to establish a frictional connectiomwith the spindle as well. i According to the construction suggestedin Figs. 5 4 and 5, the transmission elements E which may conveniently consist of three leaf springs areinwardly bowed endwise with the opposite ends 25 transversely bowed for point contact with the circular wall; Each spring itself itadapted for o,

point contact in its middle region with the spindle. Such a formation of the transmissionelements will produce a degree of friction between the spindle and circular wall suflicient to establish a driving connection by, which rotation 15 of the turntable will be assure Fromthe foregoing description'it will be apparent thatI have developed a novel and effective transmission by which to establish a releasable friction drive between a spindle and phonograph d turntable, the several parts being inexpensive to produceand assemble,and being tensioned only when the turntable is positioned for opera? I claim: j 1. A driving connection between a spindle and tion upon the spindle; V

turntable comprising a plurality of springs'each having a curved portion in frictional engagementwith the spindle and all together, engaging therewith throughout substantially 360, and. means connecting the springs frictionally with the turntable, the degree of, friction between the springs and turntable being increased sumciently to establisha driving connection therewith when,

the springs are in frictional engagement with the spindle. a 2. A driving connection between a. spindle and turntable comprising a plurality of coacting resilient transmission elements each adapted to engage with the spindle, and means in connection with the turntable with which the transmission elements are adapted to frictionally engage, the transmission elements being placed under tension when the spindle is in engagement therewith whereby a frictional driving connection is completed between the spindle, transmission elements and turntable.

3. A drivng connection between a spindleand turntable com-prising a plurality of bowed leaf springs each adapted to frictionally engage with 50 the spindle, and means in connection withthe turntable with which the springs are adapted to frictionally engage, the springs being placed under tension when the spindle is in engagement therewith whereby a frictional driving con- 5 adapted to trictionally engage, the transmission elements being placed under tension when the spindle is in engagement therewith whereby a frictional driving connection is completed between the spindle. transmission elements and 5 turntable hub.

JOSEPH ERWOOD. 

